1. Roland amp will work. As to "perfectly replicate", well, that's subjective will depend on you. I have a Yamaha MS50DR and it's good. You may also find a full range PA setup is good. All down to budget and what you are trying to achieve and personal taste.
2. Maximum pads? One for every input - 10 on that module I think. Unfortunately, I don't think that unit has MIDI IN
3. Cleaning? Aerospace 303.